Common banknote processing devices sort and stack banknotes placed on a hopper into plural staking units according to predetermined criteria. In contrast, banknote processing devices of Patent Documents 1 and 2 that efficiently sort more kinds of banknotes than the number of staking units are known.
The banknote processing device of Patent Document 1 stacks into one of three stacking units, banknotes that have failed to be sorted into the other two stacking units. In the banknote processing device of Patent Document 1, banknotes of designated denominations are sorted and stacked into the two stacking units, while banknotes of mixed denominations are stacked in the remaining stacking unit. Accordingly, the banknotes of the mixed denominations need to be placed again on the hopper and sorted. That is, when there are four or more denominations, the sorting process needs to be performed at least twice.
On the other hand, the banknote processing device of Patent Document 2 has seven stacking units and does not need to perform the sorting process twice or more times when there are seven or less denominations. However, when the number of stacking units increases, the size of the banknote processing device is enlarged, and the production cost increases accordingly. Further, some stacking units are unused depending on the number of denominations of banknotes to be sorted.
Both in the banknote processing devices of Patent Documents 1 and 2, the sorted banknotes and the banknotes having failed to be sorted are stacked in the stacking units arranged at lower positions of the devices. Therefore, it is difficult to know which stacking unit contains the banknotes having failed to be sorted.
[Patent Document 1] Japanese Patent Application Laid-open No. 2005-165805
[Patent Document 2] Japanese Patent Application Laid-open No. 2002-74464